1. Field of the Invention
The present invention relates to an automatic cup drink vending machine. More specifically, the present invention relates to an automatic cup drink vending machine capable of vending cold drinks in a postmix fashion.
2. Description of the Prior Art
An automatic cup drink vending machine can vend cold drinks or hot drinks. The known automatic cup drink vending machines for vending cold drinks may be classified into two types, i.e. a postmix type and a premix type. Vending machines of a postmix type are adapted such that at each cup vending a source material such as a concentrated source liquid or source powder is mixed with water or cold water in the automatic vending machine, whereupon the mixture is poured into a cup. In some vending machines of the postmix type, ice is further put into a cup being vended, so that colder drinks can be vended. On the other hand, vending machines of the premix type are adapted such that drinks as mixed in advance are stored and are guided into a cup while the drinks are cooled. The present invention is directed to an improvement in an automatic cup drink vending machine for vending cold drinks in a postmix fashion.
Known cup cold drink automatic vending machines of the postmix type may be divided into four groups. Vending machines of the first group are structured such that a cup for vending is brought to a vending position, ice say 70 g is in advance put into the cup, and a hot concentrated source liquid obtained by mixing hot water of say 70 cc heated to say 90.degree. C. with source powder is poured into the cup with the ice of 70 g contained therein. Accordingly, the hot water in which the source powder is dissolved is cooled by the ice in the cup, so that a cold drink of approximately 140 cc can be vended. The vending machines of the second group are structured such that similarly ice of approximately 50 g is put into a cup for vending, source powder is dissolved into hot water of say 90 cc heated to say 90.degree. C., the solution or a concentrated source liquid is cooled by a cooler and then the cooled mixture is poured into the cup as a cold drink. The vending machines of the third group are structured such that similarly ice of approximately 40 g is stored in advance, source powder is dissolved into hot water of approximately 30 cc heated to approximately 90.degree. C. and then cold water of approximately 70 cc is poured into the hot mixture, whereby a cold drink of approximately 100 cc cooled to approximately 15.degree. C. is obtained as a mixture, which is then poured into the cup. The vending machines of the fourth group are structured such that similarly ice of say 40 g is stored in a cup for vending, a concentrated source liquid as cooled by a cooler and cold water as similarly cooled by the cooler are both introduced into the cup, whereby the concentrated source liquid and the cold water are mixed in the cup.
Prior art vending machines of the postmix type have the following disadvantages. More specifically, according to the above described first vending machine group, since a hot drink is poured into a cup in which ice has been put in advance, whereby the hot drink is converted into a cold drink in the cup by virtue of the ice, it is difficult to attain a uniform temperature distribution of the cold drink in the cup, with the result that a temperature distribution is caused such that a lower portion is relatively warm while the upper portion is relatively cold by virtue of the ice. Furthermore, since relatively more ice is put in advance into the cup, the number of cups that can be consecutively vended is limited by the capacity of an ice storing portion for storing the ice within the machine. Nevertheless, an attempt to eliminate such problem requires that a larger quantity of ice be stored, which requires a large size ice storing means and thus increases the size of the whole apparatus. On the other hand, with the above described second group of the vending machines, the temperature of the drinks being vended cannot be sufficiently lowered, unless a relatively powerful cooler is employed. Furthermore, in case of any of the above described second, third and fourth groups of vending machines, it is required to employ two refrigerating cycles, i.e. a first refrigerating cycle for making ice and a second refrigerating cycle for cooling water or making cold water. Accordingly, the machines become complicated and the cost becomes expensive. Furthermore, generally the refrigerating cycle for making cold water is not energy sufficient, which is undesirable from an energy conservation point of view.